mirror of
https://gitee.com/bianbu-linux/linux-6.6
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a9ff696160
Making virt_to_pfn() a static inline taking a strongly typed (const void *) makes the contract of a passing a pointer of that type to the function explicit and exposes any misuse of the macro virt_to_pfn() acting polymorphic and accepting many types such as (void *), (unitptr_t) or (unsigned long) as arguments without warnings. Doing this is a bit intrusive: virt_to_pfn() requires PHYS_PFN_OFFSET and PAGE_SHIFT to be defined, and this is defined in <asm/page.h>, so this must be included *before* <asm/memory.h>. The use of macros were obscuring the unclear inclusion order here, as the macros would eventually be resolved, but a static inline like this cannot be compiled with unresolved macros. The naive solution to include <asm/page.h> at the top of <asm/memory.h> does not work, because <asm/memory.h> sometimes includes <asm/page.h> at the end of itself, which would create a confusing inclusion loop. So instead, take the approach to always unconditionally include <asm/page.h> at the end of <asm/memory.h> arch/arm uses <asm/memory.h> explicitly in a lot of places, however it turns out that if we just unconditionally include <asm/memory.h> into <asm/page.h> and switch all inclusions of <asm/memory.h> to <asm/page.h> instead, we enforce the right order and <asm/memory.h> will always have access to the definitions. Put an inclusion guard in place making it impossible to include <asm/memory.h> explicitly. Link: https://lore.kernel.org/linux-mm/20220701160004.2ffff4e5ab59a55499f4c736@linux-foundation.org/ Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
111 lines
2.6 KiB
C
111 lines
2.6 KiB
C
/* SPDX-License-Identifier: GPL-2.0-only */
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#ifndef __ASM_UACCESS_ASM_H__
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#define __ASM_UACCESS_ASM_H__
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#include <asm/asm-offsets.h>
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#include <asm/domain.h>
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#include <asm/page.h>
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#include <asm/thread_info.h>
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.macro csdb
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#ifdef CONFIG_THUMB2_KERNEL
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.inst.w 0xf3af8014
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#else
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.inst 0xe320f014
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#endif
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.endm
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.macro check_uaccess, addr:req, size:req, limit:req, tmp:req, bad:req
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#ifndef CONFIG_CPU_USE_DOMAINS
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adds \tmp, \addr, #\size - 1
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sbcscc \tmp, \tmp, \limit
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bcs \bad
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#ifdef CONFIG_CPU_SPECTRE
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movcs \addr, #0
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csdb
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#endif
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#endif
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.endm
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.macro uaccess_mask_range_ptr, addr:req, size:req, limit:req, tmp:req
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#ifdef CONFIG_CPU_SPECTRE
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sub \tmp, \limit, #1
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subs \tmp, \tmp, \addr @ tmp = limit - 1 - addr
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addhs \tmp, \tmp, #1 @ if (tmp >= 0) {
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subshs \tmp, \tmp, \size @ tmp = limit - (addr + size) }
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movlo \addr, #0 @ if (tmp < 0) addr = NULL
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csdb
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#endif
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.endm
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.macro uaccess_disable, tmp, isb=1
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#ifdef CONFIG_CPU_SW_DOMAIN_PAN
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/*
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* Whenever we re-enter userspace, the domains should always be
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* set appropriately.
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*/
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mov \tmp, #DACR_UACCESS_DISABLE
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mcr p15, 0, \tmp, c3, c0, 0 @ Set domain register
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.if \isb
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instr_sync
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.endif
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#endif
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.endm
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.macro uaccess_enable, tmp, isb=1
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#ifdef CONFIG_CPU_SW_DOMAIN_PAN
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/*
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* Whenever we re-enter userspace, the domains should always be
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* set appropriately.
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*/
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mov \tmp, #DACR_UACCESS_ENABLE
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mcr p15, 0, \tmp, c3, c0, 0
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.if \isb
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instr_sync
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.endif
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#endif
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.endm
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#if defined(CONFIG_CPU_SW_DOMAIN_PAN) || defined(CONFIG_CPU_USE_DOMAINS)
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#define DACR(x...) x
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#else
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#define DACR(x...)
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#endif
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/*
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* Save the address limit on entry to a privileged exception.
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*
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* If we are using the DACR for kernel access by the user accessors
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* (CONFIG_CPU_USE_DOMAINS=y), always reset the DACR kernel domain
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* back to client mode, whether or not \disable is set.
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*
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* If we are using SW PAN, set the DACR user domain to no access
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* if \disable is set.
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*/
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.macro uaccess_entry, tsk, tmp0, tmp1, tmp2, disable
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DACR( mrc p15, 0, \tmp0, c3, c0, 0)
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DACR( str \tmp0, [sp, #SVC_DACR])
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.if \disable && IS_ENABLED(CONFIG_CPU_SW_DOMAIN_PAN)
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/* kernel=client, user=no access */
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mov \tmp2, #DACR_UACCESS_DISABLE
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mcr p15, 0, \tmp2, c3, c0, 0
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instr_sync
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.elseif IS_ENABLED(CONFIG_CPU_USE_DOMAINS)
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/* kernel=client */
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bic \tmp2, \tmp0, #domain_mask(DOMAIN_KERNEL)
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orr \tmp2, \tmp2, #domain_val(DOMAIN_KERNEL, DOMAIN_CLIENT)
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mcr p15, 0, \tmp2, c3, c0, 0
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instr_sync
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.endif
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.endm
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/* Restore the user access state previously saved by uaccess_entry */
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.macro uaccess_exit, tsk, tmp0, tmp1
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DACR( ldr \tmp0, [sp, #SVC_DACR])
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DACR( mcr p15, 0, \tmp0, c3, c0, 0)
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.endm
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#undef DACR
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#endif /* __ASM_UACCESS_ASM_H__ */
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